Post by cye on Mar 18, 2019 4:18:52 GMT -5
This mini-project was to rig up a small panel for use on a yacht.
The informal 'design brief' given by the boat owner was that the mounting facility should enable him to orient the panel in any direction and at any inclination, all easily adjustable if required, that it was to be mounted on a 1" vertical pole, and that the panel should be capable of trickle-charging a 12v battery with a capacity in the range of 100-120ah - All without a charge controller!
Pics here shows me testing the rig in the back garden mounted to a 1" pipe held vertically by my bicycle maintenance stand.
Panel size - If one is not a using charge controller and one is to avoid cooking the battery , the rule of thumb here is that the max wattage of the 12v panel should be in the range of 5-10% of the capacity of the 12v battery. So, 100ah battery * 10% = 10 then tells us the panel wattage should be no more than 10w. Note that a '12v panel' is typically 18v OCV (open circuit voltage).
To the back of the panel I fixed 3 length of salvaged aluminium from a storm-damaged greenhouse.
To this I then fixed a section of aluminium angle (from old dexion shelving unit?).
The parts needed to allow the panel to be fixed in any orientation and any inclination are as follows:
[1] Bicycle handlebar (suitably shortened)
[2] Bicycle handlebar clamp (used to fix the handlebar to the steering tube of an A-head type bicycle fork)
[3] To fix the handlebar to the aluminium angle, I used two motorcycle handlebar clamps used to hold mirrors.
The watt meter is not a permanent feature, only used here for testing. However, in the same pic you can see I have fitted a schottky diode as a 'blocking diode' to prevent the battery discharging through the panel. Interestingly, the panel spec stated that a blocking diode was built into the panel, however, inside the panel's black connector box was only a diode soldered across the positive and negative - As such, the panel had actually been manufactured only with a bypass diode and not a blocking diode. The panel spec was therefore incorrect!
The informal 'design brief' given by the boat owner was that the mounting facility should enable him to orient the panel in any direction and at any inclination, all easily adjustable if required, that it was to be mounted on a 1" vertical pole, and that the panel should be capable of trickle-charging a 12v battery with a capacity in the range of 100-120ah - All without a charge controller!
Pics here shows me testing the rig in the back garden mounted to a 1" pipe held vertically by my bicycle maintenance stand.
Panel size - If one is not a using charge controller and one is to avoid cooking the battery , the rule of thumb here is that the max wattage of the 12v panel should be in the range of 5-10% of the capacity of the 12v battery. So, 100ah battery * 10% = 10 then tells us the panel wattage should be no more than 10w. Note that a '12v panel' is typically 18v OCV (open circuit voltage).
To the back of the panel I fixed 3 length of salvaged aluminium from a storm-damaged greenhouse.
To this I then fixed a section of aluminium angle (from old dexion shelving unit?).
The parts needed to allow the panel to be fixed in any orientation and any inclination are as follows:
[1] Bicycle handlebar (suitably shortened)
[2] Bicycle handlebar clamp (used to fix the handlebar to the steering tube of an A-head type bicycle fork)
[3] To fix the handlebar to the aluminium angle, I used two motorcycle handlebar clamps used to hold mirrors.
The watt meter is not a permanent feature, only used here for testing. However, in the same pic you can see I have fitted a schottky diode as a 'blocking diode' to prevent the battery discharging through the panel. Interestingly, the panel spec stated that a blocking diode was built into the panel, however, inside the panel's black connector box was only a diode soldered across the positive and negative - As such, the panel had actually been manufactured only with a bypass diode and not a blocking diode. The panel spec was therefore incorrect!
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